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BUG: KCSAN: data-race in do_sys_poll / pollwake

write to 0xffffc900001c3bd0 of 4 bytes by task 4320 on cpu 1:
 __pollwake fs/select.c:195 [inline]
 pollwake+0xc1/0x110 fs/select.c:215
 __wake_up_common kernel/sched/wait.c:89 [inline]
 __wake_up_common_lock kernel/sched/wait.c:106 [inline]
 __wake_up+0x65/0xb0 kernel/sched/wait.c:127
 ep_poll_safewake fs/eventpoll.c:657 [inline]
 ep_poll_callback+0x4e3/0x600 fs/eventpoll.c:1418
 __wake_up_common kernel/sched/wait.c:89 [inline]
 __wake_up_common_lock kernel/sched/wait.c:106 [inline]
 __wake_up+0x65/0xb0 kernel/sched/wait.c:127
 ep_poll_safewake fs/eventpoll.c:657 [inline]
 ep_poll_callback+0x4e3/0x600 fs/eventpoll.c:1418
 __wake_up_common kernel/sched/wait.c:89 [inline]
 __wake_up_common_lock kernel/sched/wait.c:106 [inline]
 __wake_up+0x65/0xb0 kernel/sched/wait.c:127
 unix_dgram_peer_wake_relay+0xd4/0xf0 net/unix/af_unix.c:511
 __wake_up_common kernel/sched/wait.c:89 [inline]
 __wake_up_common_lock kernel/sched/wait.c:106 [inline]
 __wake_up_sync_key+0x51/0x80 kernel/sched/wait.c:173
 __unix_dgram_recvmsg+0x3bf/0x890 net/unix/af_unix.c:2447
 unix_dgram_recvmsg+0x81/0x90 net/unix/af_unix.c:2522
 sock_recvmsg_nosec+0x107/0x140 net/socket.c:1017
 ____sys_recvmsg+0x27b/0x290 net/socket.c:2784
 ___sys_recvmsg net/socket.c:2828 [inline]
 do_recvmmsg+0x2a1/0x6e0 net/socket.c:2923
 __sys_recvmmsg net/socket.c:2997 [inline]
 __do_sys_recvmmsg net/socket.c:3020 [inline]
 __se_sys_recvmmsg net/socket.c:3013 [inline]
 __x64_sys_recvmmsg+0xe4/0x170 net/socket.c:3013
 x64_sys_call+0x1b90/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:300
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffc900001c3bd0 of 4 bytes by task 4327 on cpu 0:
 poll_schedule_timeout fs/select.c:240 [inline]
 do_poll fs/select.c:958 [inline]
 do_sys_poll+0x9f1/0xc80 fs/select.c:1009
 __do_sys_ppoll fs/select.c:1115 [inline]
 __se_sys_ppoll+0x1b5/0x1f0 fs/select.c:1095
 __x64_sys_ppoll+0x67/0x80 fs/select.c:1095
 x64_sys_call+0x2c89/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:272
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 4327 Comm: syz.4.296 Not tainted 6.15.0-rc1-syzkaller-00333-g5aaaedb0cb54 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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